Synthesis of variously oxidized abietane diterpenes and their antibacterial activities against MRSA and VRE

Variously oxidized 12 natural abietanes, 6,7-dehydroferruginol methyl ether (3), ferruginol (5), 11-hydroxy-12-oxo-7,9(11),13-abietatriene (7), roylea none (9), demethyl cryptojaponol (12), salvinolone (14), sugiol methyl ethe r (16), sugiol (17), 5,6-dehydrosugiol methyl ether (19), 5,6-dehydrosugiol (20), 6 beta -hydroxyferruginol (23), and taxodione (25) were synthesized. Antimicrobial activities of synthesized phenolic diterpenes and their rela ted compounds against MRSA and VRE were evaluated. Phenols (12-hydroxyabiet a-8,11,13-trien-6-one 22 and 23), catechols (12 and 14) and taxodione 25 sh owed potent activity with 4-10 mug/mL of MIC against MRSA and 4-16 mug/mL o f MIC against VRE. (-)-Ferruginol showed more potent activity than natural type (+)-ferruginol. Quinone methide 7 showed the most potent activity with 0.5-1 mug/mL of MIC against both MRSA and VRE. (C) 2001 Elsevier Science L td. All rights reserved.